Light-emitting device and manufacturing method thereof

ABSTRACT

A light-emitting device including at least one light-emitting unit, a wavelength conversion adhesive layer, and a reflective protecting element is provided. The light-emitting unit has an upper surface and a lower surface opposite to each other. The light-emitting unit includes two electrode pads, and the two electrode pads are located on the lower surface. The wavelength conversion adhesive layer is disposed on the upper surface. The wavelength conversion adhesive layer includes a low-concentration fluorescent layer and a high-concentration fluorescent layer. The high-concentration fluorescent layer is located between the low-concentration fluorescent layer and the light-emitting unit. The width of the high-concentration fluorescent layer is W H . The width of the low-concentration fluorescent layer is W L . The width of the light-emitting unit is W E . The light-emitting device further satisfies the following inequalities: W E &lt;W L , W H &lt;W L  and 0.8&lt;W H /W E ≤1.2. Furthermore, a manufacturing method of the light-emitting device is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the prioritybenefit of U.S. application Ser. No. 15/788,757, filed on Oct. 19, 2017,now allowed. The prior U.S. application Ser. No. 15/788,757 is acontinuation-in-part application of and claims the priority benefit ofU.S. application Ser. No. 15/268,654, filed on Sep. 19, 2016, nowpatented. The prior U.S. application Ser. No. 15/788,757 also claims thepriority benefit of U.S. provisional application Ser. No. 62/410,373,filed on Oct. 19, 2016. This prior U.S. application Ser. No. 15/268,654is a continuation-in-part application of and claims the priority benefitof U.S. application Ser. No. 14/711,798, filed on May 14, 2015, nowabandoned, which claims the priority benefits of Taiwan applicationserial no. 103116987, filed on May 14, 2014 and U.S. provisionalapplication Ser. No. 62/157,450, filed on May 5, 2015. This prior U.S.application Ser. No. 15/268,654 also claims the priority benefits ofU.S. provisional application Ser. No. 62/220,249, filed on Sep. 18,2015, U.S. provisional application Ser. No. 62/236,150, filed on Oct. 2,2015, Taiwan application serial no. 105100499, filed on Jan. 8, 2016,U.S. provisional application Ser. No. 62/245,247, filed on Oct. 22,2015, U.S. provisional application Ser. No. 62/262,876, filed on Dec. 3,2015, and China application serial no. 201610293182.5, filed on May 5,2016. The entirety of each of the above-mentioned patent applications ishereby incorporated by reference herein and made a part of thisspecification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a light-emitting device and a manufacturingmethod thereof, and more particularly, to a light-emitting device forwhich an LED is used as the light source and a manufacturing methodthereof.

Description of Related Art

In a regular white LED structure, a layer of yellow phosphor is coveredon a blue LED chip. The mechanism with which the white LED structureemits white light includes emitting blue light via a blue LED chip,wherein a portion of the blue light passes through the yellow phosphoron top and is converted into yellow light, and the yellow light iscombined with blue light from other portions to achieve the effect ofwhite light emission. Since the blue light emitted by the blue LED chiphas a higher degree of directivity, blue light deviated from the opticalaxis at a greater angle is weaker, and blue light closer to the opticalaxis is stronger. Therefore, when blue light is irradiated onfluorescent powder at different intensities, the color temperature ofwhite light correspondingly emitted closer to the optical axis is higher(i.e., blue ratio is high) and the color temperature of white lightcorrespondingly emitted farther from the optical axis is lower (i.e.,blue light ratio is low). The phenomenon is also referred to as yellowcircle phenomenon, and the color temperature of the light from the whiteLED structure is not uniform as a result.

SUMMARY OF THE INVENTION

The invention provides a light-emitting device having a uniform lightcolor temperature.

The invention provides a manufacturing method of the light-emittingdevice. The color temperature of light emitted from the resultinglight-emitting device is uniform.

An embodiment of the invention provides a light-emitting deviceincluding at least one light-emitting unit, a wavelength conversionadhesive layer, and a reflective protecting element. The light-emittingunit has an upper surface and a lower surface opposite to each other.The light-emitting unit includes two electrode pads, and the twoelectrode pads are located on the lower surface of the light-emittingunit. The wavelength conversion adhesive layer is disposed on the uppersurface of the light-emitting unit. The wavelength conversion adhesivelayer includes a low-concentration fluorescent adhesive layer and ahigh-concentration fluorescent adhesive layer, and thehigh-concentration fluorescent adhesive layer is located between thelow-concentration fluorescent adhesive layer and the light-emittingunit. The reflective protecting element covers the light-emitting unitand a portion of the wavelength conversion adhesive layer and at leastexposes the two electrode pads of the light-emitting unit and thelow-concentration fluorescent layer. The width of the high-concentrationfluorescent layer is W_(H). The width of the low-concentrationfluorescent layer is W_(L). The width of the light-emitting unit isW_(E). The light-emitting device further satisfies the followinginequalities: W_(E)<W_(L), W_(H)<W_(L) and 0.8<W_(H)/W_(E)≤1.2.

In an embodiment of the invention, the wavelength conversion adhesivelayer further includes a first mesa portion and a plurality of secondmesa portions. The first mesa portion includes the high-concentrationfluorescent adhesive layer and a first portion of the low-concentrationfluorescent adhesive layer, each of the second mesa portions includes asecond portion of the low-concentration fluorescent adhesive layer, andthe first portion of the low-concentration fluorescent adhesive layer isconnected to the second portion of the low-concentration fluorescentadhesive layer.

In an embodiment of the invention, the reflective protecting element hasa concave surface, and the concave surface is recessed toward thewavelength conversion adhesive layer.

In an embodiment of the invention, the light-emitting device furtherincludes a translucent adhesive layer. The light-emitting unit furtherincludes a side surface connected to the upper surface and the lowersurface. The translucent adhesive layer is disposed on thelow-concentration fluorescent adhesive layer and extended to the sidesurface of the light-emitting unit.

In an embodiment of the invention, the reflective protecting elementcovers the wavelength conversion adhesive layer and exposes a portion ofthe side of the wavelength conversion adhesive layer.

In an embodiment of the invention, the reflective protecting element hasa reflective surface, and the reflective surface is in contact with thelight-emitting unit.

In an embodiment of the invention, the first side of the reflectivesurface is in contact with the light-emitting unit, and the second sideof the reflective surface is extended toward the wavelength conversionadhesive layer and away from the light-emitting unit.

In an embodiment of the invention, the reflective surface is a curvedsurface.

An embodiment of the invention provides a manufacturing method of alight-emitting device including forming a wavelength conversion adhesivelayer, wherein the wavelength conversion adhesive layer includes alow-concentration fluorescent adhesive layer and a high-concentrationfluorescent adhesive layer. A plurality of light-emitting units isprovided. A plurality of trenches is formed in the wavelength conversionadhesive layer to define a plurality of bonding regions between thetrenches. In the bonding regions, the width of the high-concentrationfluorescent adhesive layer is W_(H), the width of the low-concentrationfluorescent adhesive layer is W_(L), the width of the light-emittingunit is W_(E), and the step further satisfies the followinginequalities: W_(E)<W_(L), W_(H)<W_(L), and 0.8<W_(H)/W_(E)≤1.2. Thelight-emitting units are respectively bonded to the high-concentrationfluorescent adhesive layers in the bonding regions. A reflectiveprotecting element is formed on the wavelength conversion adhesive layerand between the light-emitting units to completely fill the trenches,wherein the reflective protecting element exposes the electrode pads ofthe light-emitting units. A cutting process is performed along thetrenches to form a plurality of light-emitting devices.

In an embodiment of the invention, the step of forming the trenches inthe wavelength conversion adhesive layer further includes removing aportion of the high-concentration fluorescent adhesive layer and aportion of the low-concentration fluorescent adhesive layer to form aplurality of first sub-trenches. The first sub-trenches respectivelyform a plurality of first mesa portions in the bonding regions, whereineach of the first mesa portions further includes a first portion of thehigh-concentration fluorescent adhesive layer and a first portion of thelow-concentration fluorescent adhesive layer. A portion of thelow-concentration fluorescent adhesive layer is removed to form aplurality of second sub-trenches in the first sub-trenches, and thesecond sub-trenches respectively form a plurality of second mesaportions in the bonding regions, wherein each of the second mesaportions further includes a second portion of the low-concentrationfluorescent adhesive layer, and the first portion of thelow-concentration fluorescent adhesive layer is connected to the secondportion of the low-concentration fluorescent adhesive layer. A trenchincludes a first sub-trench and a second sub-trench.

In an embodiment of the invention, before the step of respectivelybonding the light-emitting units to the high-concentration fluorescentadhesive layers in the bonding regions, a plurality of translucentadhesive layers is respectively formed on the high-concentrationfluorescent adhesive layers in the bonding regions.

In an embodiment of the invention, in the step of respectively bondingthe light-emitting units to the high-concentration fluorescent adhesivelayers in the bonding regions, the light-emitting units are respectivelybonded to the high-concentration fluorescent adhesive layers via thetranslucent adhesive layers.

In an embodiment of the invention, after the step of forming thereflective protecting element on the wavelength conversion adhesivelayer and between the light-emitting units to completely fill thetrenches, the reflective protecting element is left to stand to form aconcave surface recessed toward the wavelength conversion adhesive layerin the reflective protecting element, and the reflective protectingelement is cured.

Based on the above, in the light-emitting device of an embodiment of theinvention, the width of the high-concentration fluorescent adhesivelayer is W_(H), the width of the low-concentration fluorescent adhesivelayer is W_(L), and the width of the light-emitting unit is W_(E). Thelight-emitting device further satisfies the following inequalities:W_(E)<W_(L), W_(H)<W_(L) and 0.8<W_(H)/W_(E)≤1.2. By satisfying theinequality design above, the color temperature of the color lightemitted by the light-emitting device of an embodiment of the inventionis more consistent at different angles. Since one of the steps of themanufacturing method of the light-emitting device of an embodiment ofthe invention satisfies the above inequalities, the color temperature ofthe color light emitted by the light-emitting device made by themanufacturing method is more consistent at different angles.

In order to make the aforementioned features and advantages of thedisclosure more comprehensible, embodiments accompanied with figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 shows a schematic of a light-emitting device of an embodiment ofthe invention.

FIG. 2 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 3 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 4 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 5 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 6 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 7 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 8 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 9 shows a schematic of a light-emitting device of anotherembodiment of the invention.

FIG. 10A to FIG. 10D show cross sections of a manufacturing method of alight-emitting device of an embodiment of the invention.

FIG. 11A to FIG. 11C show cross sections of some of the steps of amanufacturing method of a light-emitting device of another embodiment ofthe invention.

FIG. 12A to FIG. 12E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention.

FIG. 13A to FIG. 13D show cross sections of some of the steps of amanufacturing method of a light-emitting device of another embodiment ofthe invention.

FIG. 14A to FIG. 14E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention.

FIG. 15A to FIG. 15E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention.

FIG. 16A to FIG. 16C show cross sections of a light-emitting device of aplurality of embodiments of the invention.

FIG. 17A to FIG. 17E show cross sections of a manufacturing method of alight-emitting device of an embodiment of the invention.

FIG. 18A and FIG. 18B show cross sections of two light-emitting devicesof two embodiments of the invention.

FIG. 19A to FIG. 19E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention.

FIG. 20A shows a 3D view of the light-emitting device of FIG. 19E.

FIG. 20B shows a cross section along line X-X of FIG. 20A.

FIG. 21A shows a 3D view of a light-emitting device of anotherembodiment of the invention.

FIG. 21B and FIG. 21C respectively show cross sections along line X′-X′and line Y′-Y′ of FIG. 21A.

FIG. 22A to FIG. 22J show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention.

FIG. 23 shows a comparison chart of color temperature of thelight-emitting device of the embodiment of FIG. 22J and a knownlight-emitting device measured at different angles.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows a schematic of a light-emitting device of an embodiment ofthe invention. Referring first to FIG. 1, in the present embodiment, alight-emitting device 100 a includes a light-emitting unit 110 a and areflective protecting element 120. The light-emitting unit 110 a has anupper surface 112 a and a lower surface 114 a opposite to each other, aside surface 116 a connected to the upper surface 112 a and the lowersurface 114 a, and a first electrode pad 113 and a second electrode pad115 located on the lower surface 114 a and separated from each other.The reflective protecting element 120 covers the side surface 116 a ofthe light-emitting unit 110 a and exposes at least a portion of theupper surface 112 a and at least a portion of a first bottom surface 113a of the first electrode pad 113 and at least a portion of a secondbottom surface 115 a of the second electrode pad 115.

More specifically, in the present embodiment, as shown in FIG. 1, theupper surface 112 a of the light-emitting unit 110 a is aligned with atop surface 122 of the reflective protecting element 120, a bottomsurface 124 of the reflective protecting element 120 is aligned with thefirst bottom surface 113 a of the first electrode pad 113 and the secondbottom surface 115 a of the second electrode pad 115, and the reflectiveprotecting element 120 can cover or expose the lower surface 114 a ofthe light-emitting unit 110 a located between the first electrode pad113 and the second electrode pad 115. In the present embodiment, theside surface 116 a of the light-emitting unit 110 a is perpendicular tothe upper surface 112 a and the lower surface 114 a, but is not limitedthereto, and the light-emitting unit 110 a is, for instance, alight-emitting diode (LED), and the emission wavelength of the LED is(including but not limited to) between 315 nm and 780 nm, and the LEDincludes, but is not limited to, UV, blue, green, yellow, orange, or redLED.

The reflectivity of the reflective protecting element 120 is at leastgreater than 90%. In other words, the reflective protecting element 120of the present embodiment has the property of high reflectivity, whereinthe material of the reflective protecting element 120 includes a polymermaterial doped with a highly reflective particle, and the highlyreflective particle is, but not limited to, for instance, titaniumdioxide (TiO₂) powder, and the highly reflective particle is, but notlimited to, for instance, epoxy resin or silicone resin. Moreover, thematerial of the first electrode pad 113 and the second electrode pad 115of the light-emitting unit 110 a of the present embodiment is a metalmaterial or metal alloy such as gold, aluminum, tin, silver, bismuth,indium, or a combination thereof, but is not limited thereto.

In the present embodiment, the reflective protecting element 120 coversthe side surface 116 a of the light-emitting unit 110 a and exposes thefirst bottom surface 113 a of the first electrode pad 113 and the secondbottom surface 115 a of the second electrode 115 of the light-emittingunit 110 a. The light-emitting device 100 a does not need a knownbearing bracket to support and fix the light-emitting unit 110 a and caneffectively reduce package thickness and manufacturing cost. At the sametime, the positive optical efficiency of the light-emitting unit 110 acan also be increased via the reflective protecting element 120 havinghigh reflectivity.

It should be mentioned here that, the following embodiments adopt thereference numerals of the embodiments above and a portion of thecontents thereof, wherein the same reference numerals are adopted torepresent the same or similar elements. Descriptions of the sametechnical content are as provided in the embodiments above and are notrepeated in the following embodiments.

FIG. 2 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 1 and FIG. 2, themain differences between a light-emitting device 100 b of the presentembodiment and the light-emitting device 100 a in FIG. 1 are that a sidesurface 116 b of the light-emitting unit 110 b of the present embodimentis not perpendicular to an upper surface 112 b and a lower surface 114b, the surface area of the upper surface 112 b is greater than thesurface area of the lower surface 114 b of the light-emitting unit 100 bin the present embodiment, and the angle between the side surface 116 band the lower surface 114 b is, for instance, between 95 degrees and 150degrees. The contour defined by the upper surface 112 b, the sidesurface 116 b, and the lower surface 114 b of the light-emitting unit110 b of the present embodiment is an inverted trapezoid, and thereforelateral emission of the light-emitting unit 110 b can be reduced, andthe reflective protecting element 120 having high reflectivity canfurther effectively increase the positive optical efficiency of thelight-emitting unit 110 b.

FIG. 3 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 1 and FIG. 3, themain difference between a light-emitting device 100 c of the presentembodiment and the light-emitting device 100 a in FIG. 1 is that thelight-emitting device 100 c of the present embodiment further includes afirst extension electrode 130 c and a second extension electrode 140 c.The first extension electrode 130 c is disposed on the bottom surface124 of the reflective protecting element 120 and electrically connectedto the first electrode pad 113. The second extension electrode 140 c isdisposed on the bottom surface 124 of the reflective protecting element120 and electrically connected to the second electrode pad 115. Thefirst extension electrode 130 c and the second extension electrode 140 care separated from each other and cover at least a portion of the bottomsurface 124 of the reflective protecting element 120.

As shown in FIG. 3, the first extension electrode 130 c and the secondextension electrode 140 c of the present embodiment are completelyoverlapped with the first electrode pad 113 and the second electrode pad115 and extended toward the edges of the reflective protecting element120. Of course, in other embodiments not shown, the first extensionelectrode 130 c and the second extension electrode 140 c can also bepartially overlapped with the first electrode pad 113 and the secondelectrode pad 115, and any configuration satisfying the condition thatthe first extension electrode 130 c and the second extension electrode140 c are electrically connected to the first electrode pad 113 and thesecond electrode pad 115 is within the scope of the present embodiment.Moreover, the first extension electrode 130 c and the second extensionelectrode 140 c of the present embodiment expose a portion of the bottomsurface 124 of the reflective protecting element 120.

In the present embodiment, the material of the first extension electrode130 c and the second extension electrode 140 c can be respectively thesame or different from that of the first electrode pad 113 and thesecond electrode pad 115 of the light-emitting unit 110 a. When thematerial of the first extension electrode 130 c and the second extensionelectrode 140 c is respectively the same as that of the first electrodepad 113 and the second electrode pad 115 of the light-emitting unit 110a, the first extension electrode 130 c and the first electrode pad 113can be seamlessly connected to form an integrally molded structure, andthe second extension electrode 140 c and the second electrode pad 115can be seamlessly connected to form an integrally molded structure. Whenthe material of the first extension electrode 130 c and the secondextension electrode 140 c is respectively different from that of thefirst electrode pad 113 and the second electrode pad 115 of thelight-emitting unit 110 a, the material of the first extension electrode130 c and the second extension electrode 140 c can be, for instance,silver, gold, bismuth, tin, indium, or an alloy of the above.

Since the light-emitting device 100 c of the present embodiment has thefirst extension electrode 130 c and the second extension electrode 140 crespectively electrically connected to the first electrode pad 113 andthe second electrode pad 115 of the light-emitting unit 110 a, theelectrode contact area of the light-emitting device 100 c can beeffectively increased to facilitate the subsequent assembly of thelight-emitting device 100 c with other external circuits to effectivelyincrease alignment accuracy and assembly efficiency. For instance, thearea of the first extension electrode 130 c is greater than the area ofthe first electrode pad 113, and the area of the second extensionelectrode 140 c is greater than the area of the second electrode pad115.

FIG. 4 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 3 and FIG. 4, themain difference between a light-emitting device 100 d of the presentembodiment and the light-emitting device 100 c in FIG. 3 is that theedges of a first extension electrode 130 d and the edges of a secondextension electrode 140 d of the present embodiment are aligned with theedges of the reflective protecting element 120.

FIG. 5 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 1 and FIG. 5, themain difference between a light-emitting device 100 e of the presentembodiment and the light-emitting device 100 a in FIG. 1 is that thelight-emitting device 100 e of the present embodiment further includes apackaging adhesive layer 150, wherein the packaging adhesive layer 150is disposed on the upper surface 112 a of the light-emitting unit 110 ato increase light extraction rate and improve light pattern. Thepackaging adhesive layer 150 can also be extended to at least a portionof the upper surface 122 of the reflective protecting element 120, andthe edges of the packaging adhesive layer 150 can also be aligned withthe edges of the reflective protecting element 120. Moreover, at leastone wavelength conversion material can also be doped inside thepackaging adhesive layer 150, and the wavelength conversion material isused for converting the wavelength of at least a portion of the lightemitted by the light-emitting unit 110 a into other wavelengths, and thewavelength conversion material includes a fluorescent material,phosphorescent material, dye, quantum dot material, or a combinationthereof, wherein the particle size of the wavelength conversion materialis, for instance, between 3 microns and 50 microns. Moreover, an oxidehaving high scattering power can also be doped inside the packagingadhesive layer 150, such as titanium dioxide (TiO₂) or silicon dioxide(SiO₂) to increase optical efficiency.

In an embodiment of the invention, the light-emitting unit includes, butis not limited to, a UV, blue, green, yellow, orange, or redlight-emitting unit, and the wavelength conversion material includes,but is not limited to, a red, orange, orange-yellow, yellow,yellow-green, or green wavelength conversion material or a combinationthereof for converting a portion or all of the wavelength of the lightemitted by the light-emitting unit. After light from the wavelengthconversion and light without wavelength conversion are mixed, thelight-emitting device emits light in a specific range of the dominantwavelength, and the light color thereof includes, but not limited to,for instance, red, orange, orange-yellow, amber, yellow, yellow-green,or green, or white light having a specific relative color temperature isemitted, and the range of the relative color temperature is, forinstance, between 2500 K and 7000 K, but is not limited thereto.

FIG. 6 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 6 and FIG. 4, themain difference between a light-emitting device 100 f of the presentembodiment and the light-emitting device 100 d in FIG. 4 is that thelight-emitting device 100 f of the present embodiment further includes apackaging adhesive layer 150, wherein the packaging adhesive layer 150is disposed on the upper surface 112 a of the light-emitting unit 110 ato increase light extraction rate and improve light pattern. Thepackaging adhesive layer 150 can also be extended to at least a portionof the upper surface 122 of the reflective protecting element 120, andthe edges of the packaging adhesive layer 150 can also be aligned withthe edges of the reflective protecting element 120. Moreover, at leastone wavelength conversion material can also be doped inside thepackaging adhesive layer 150, the wavelength conversion material is usedfor converting the wavelength of at least a portion of the light emittedby the light-emitting unit 110 a into other wavelengths, and thewavelength conversion material includes a fluorescent material,phosphorescent material, dye, quantum dot material, or a combinationthereof, wherein the particle size of the wavelength conversion materialis, for instance, between 3 microns and 50 microns. Moreover, an oxidehaving high scattering power can also be doped inside the packagingadhesive layer 150, such as titanium dioxide (TiO₂) or silicon dioxide(SiO₂) to increase optical efficiency.

It should be mentioned that, in the embodiments of FIG. 4 and FIG. 6,the edges of the first extension electrode 130 d and the edges of thesecond extension electrode 140 d are aligned with the edges of thereflective protecting element 120. This design not only can expand thecontact area of the electrode, but in the manufacturing process, thereflective protecting element 120 can package a plurality oflight-emitting units 110 a separated from one another at the same time,and then a patterned metal layer is formed to respectively form thefirst extension electrode 130 d and the second extension electrode 140d, and then cutting is performed such that the edges of the firstextension electrode 130 d and the edges of the second extensionelectrode 140 d of each of the light-emitting devices 100 f are alignedwith the edges of the reflective protecting element 120 to effectivelyreduce process time.

FIG. 7 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 7 and FIG. 5, themain difference between a light-emitting device 100 g of the presentembodiment and the light-emitting device 100 e in FIG. 5 is that thelight-emitting device 100 g of the present embodiment further includes atranslucent layer 160 disposed on the packaging adhesive layer 150,wherein the light transmittance of the translucent layer 160 is, forinstance, greater than 50%. In the present embodiment, the material ofthe translucent layer 160 is, for instance, glass, ceramic, resin,acrylic, or silicone, and the object thereof is to guide the lightgenerated by the light-emitting unit 110 a to the outside to effectivelyincrease luminous flux and light extraction rate of the light-emittingdevice 100 g, and the light-emitting unit 110 a can also be effectivelyprotected to block outside water vapor and oxygen.

FIG. 8 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 8 and FIG. 7, themain difference between a light-emitting device 100 h of the presentembodiment and the light-emitting device 100 g in FIG. 7 is that atranslucent layer 160′ of the light-emitting device 100 h of the presentembodiment is disposed between the upper surface 110 a of thelight-emitting unit 110 a and the packaging adhesive layer 150.

FIG. 9 shows a schematic of a light-emitting device of anotherembodiment of the invention. Referring to both FIG. 9 and FIG. 6, themain difference between a light-emitting device 100 i of the presentembodiment and the light-emitting device 100 f in FIG. 6 is that thelight-emitting device 100 i of the present embodiment further includes atranslucent layer 160 disposed on the packaging adhesive layer 150,wherein the light transmittance of the translucent layer 160 is, forinstance, greater than 50%. In the present embodiment, the material ofthe translucent layer 160 is, for instance, glass, ceramic, resin,acrylic, or silicone, and the object thereof is to guide the lightgenerated by the light-emitting unit 110 a to the outside to effectivelyincrease the luminous flux and light extraction rate of thelight-emitting device 100 i, and the light-emitting unit 110 a can alsobe effectively protected to block outside water vapor and oxygen.

In the following, the light-emitting devices 100 a, 100 g, 100 d, and100 i in FIG. 1, FIG. 7, FIG. 4, and FIG. 9 are exemplified, and themanufacturing method of the light-emitting device of the invention isdescribed in detail respectively with FIG. 10A to FIG. 10D, FIG. 11A toFIG. 11C, FIG. 12A to FIG. 12E, and FIG. 13A to FIG. 13D.

FIG. 10A to FIG. 10D show cross sections of a manufacturing method of alight-emitting device of an embodiment of the invention. First,referring to FIG. 10A, a plurality of light-emitting units 110 a isdisposed on a substrate 10, wherein each of the light-emitting units 110a has an upper surface 112 a and a lower surface 114 a opposite to eachother, a side surface 116 a connected to the upper surface 112 a and thelower surface 114 a, and a first electrode pad 113 and a secondelectrode pad 115 located on the lower surface 114 a and separated fromeach other. The first electrode pad 113 and the second electrode pad 115of each of the light-emitting units 110 a are disposed on the substrate10. In other words, the light-emitting surface of the light-emittingunit 110 a, i.e., the upper surface 112 a, is relatively far from thesubstrate 10. In the embodiment, the material of the substrate 10 is,for instance, stainless steel, ceramic, or other non-conductivematerials. The light-emitting unit 110 a is, for instance, an LED, andthe emission wavelength of the LED is (including but not limited to)between 315 nm and 780 nm, and the LED includes, but is not limited to,UV, blue, green, yellow, orange, or red LED.

Next, referring to FIG. 10B, a reflective protecting element 120′ isformed on the substrate 10, wherein the reflective protecting element120′ covers each of the light-emitting units 110 a. In other words, thereflective protecting element 120′ completely and directly covers theupper surface 112 a, the lower surface 114 a, and the side surface 116 aof the light-emitting unit 110 a and completely fills the gap betweenthe first electrode pad 113 and the second electrode pad 115. Here, thereflectivity of the reflective protecting element 120′ is at leastgreater than 90%. In other words, the reflective protecting element 120′of the present embodiment can have the property of high reflectivity,wherein the material of the reflective protecting element 120′ includesa polymer material doped with a highly reflective particle, and thehighly reflective particle is, but not limited to, for instance,titanium dioxide (TiO₂) powder, and the highly reflective particle is,but not limited to, for instance, epoxy resin or silicone resin.

Next, referring to FIG. 10C, a portion of the reflective protectingelement 120′ is removed to form the reflective protecting element 120,wherein the reflective protecting element 120 exposes at least a portionof the upper surface 112 a of each of the light-emitting units 110 a. Atthis point, the upper surface 112 a of each of the light-emitting units110 a may be aligned with the top surface 122 of the reflectiveprotecting element 120. At this point, the method of removing a portionof the reflective protecting element 120′ includes, for instance, apolishing method.

Next, referring to FIG. 10D, a cutting process is performed to cut thereflective protecting element 120 along a cutting line L to form aplurality of light-emitting devices 100 a separated from one another,wherein each of the light-emitting devices 100 a respectively has atleast one light-emitting unit 110 a and a reflective protecting element120, and the reflective protecting element 120 covers the side surface116 a of the light-emitting unit 110 a and exposes at least a portion ofthe upper surface 112 a thereof.

Lastly, referring further to FIG. 10D, the substrate 10 is removed toexpose the bottom surface 124 of the reflective protecting element 120of each of the light-emitting devices 100 a and expose at least aportion of the first bottom surface 113 a of the first electrode pad 113and at least a portion of the second bottom surface 115 a of the secondelectrode pad 115 of each of the light-emitting devices 100 a.

FIG. 11A to FIG. 11C show cross sections of some of the steps of amanufacturing method of a light-emitting device of another embodiment ofthe invention. The main difference between the manufacturing method ofthe light-emitting device of the present embodiment and themanufacturing method of the light-emitting device in FIG. 10A to FIG.10D is that, between the steps of FIG. 10C and FIG. 10D, that is, aftera portion of the reflective protecting element 120′ is removed andbefore the cutting process is performed, referring to FIG. 11A, thepackaging adhesive layer 150 is formed on the light-emitting unit 110 aand the reflective protecting element 120 to increase light extractionrate and improve light pattern. Here, the packaging adhesive layer 150covers the upper surface 112 a of the light-emitting unit 110 a and thetop surface 122 of the reflective protecting element 120, and at leastone wavelength conversion material can also be doped inside thepackaging adhesive layer 150. The description of the wavelengthconversion material is as provided in the embodiments above. Moreover,an oxide having high scattering power can also be doped inside thepackaging adhesive layer 150, such as titanium dioxide (TiO₂) or silicondioxide (SiO₂) to increase optical efficiency.

Next, referring to FIG. 11B, a translucent layer 160 is formed on thelight-emitting unit 110 a and the reflective protecting element 120,wherein the translucent layer 160 is located on the packaging adhesivelayer 150 and covers the packaging adhesive layer 150. For instance, thelight transmittance of the translucent layer 160 is greater than 50%. Inthe present embodiment, the material of the translucent layer 160 is,for instance, glass, ceramic, resin, acrylic, or silicone, and theobject thereof is to guide the light generated by the light-emittingunit 110 a to the outside to effectively increase the luminous flux andlight extraction rate of the subsequent light-emitting unit packagingstructure 100 g, and the light-emitting unit 110 a can also beeffectively protected to block outside water vapor and oxygen.

Next, referring to FIG. 11C, a cutting process is performed to cut thetranslucent layer 160, the packaging adhesive layer 150, and thereflective protecting element 120 along the cutting line L to form aplurality of light-emitting devices 100 g separated from one another.Lastly, referring further to FIG. 11C, the substrate 10 is removed toexpose the bottom surface 124 of the reflective protecting element 120of each of the light-emitting devices 100 g, wherein the bottom surface124 of the reflective protecting element 120 of each of thelight-emitting devices 100 g exposes at least a portion of the firstbottom surface 113 a of the first electrode pad 113 and at least aportion of the second bottom surface 115 a of the second electrode pad115. In another embodiment of the invention, the substrate 10 can alsobe removed first before a cutting process is performed.

FIG. 12A to FIG. 12E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention. Referringfirst to FIG. 12A, the main difference between the manufacturing methodof the light-emitting device of the present embodiment and themanufacturing method of the light-emitting device in FIG. 10A to FIG.10D is that, referring to FIG. 12A, the light-emitting unit 110 a of thepresent embodiment is not in contact with the substrate 10 via the firstelectrode pad 113 and the second electrode pad 115, but is in contactwith the substrate 10 via the upper surface 112 a thereof.

Next, referring to FIG. 12B, a reflective protecting element 120′ isformed on the substrate, wherein the reflective protecting elementcovers each of the light-emitting units 110 a.

Next, referring to FIG. 12C, a portion of the reflective protectingelement 120′ is removed to form the reflective protecting element 120,wherein the reflective protecting element 120 exposes at least a portionof the first bottom surface 113 a of the first electrode pad 113 and atleast a portion of the second bottom surface 115 a of the secondelectrode pad 115 of each of the light-emitting units 110 a.

Next, referring to FIG. 12D, a patterned metal layer is formed as anextension electrode layer E located on the first bottom surface 113 a ofthe first electrode pad 113 and on the second bottom surface 115 a ofthe second electrode pad 115 of each of the light-emitting unit 110 a.Here, the method of forming the patterned metal layer includes, forinstance, evaporation, sputtering, electroplating, or electrolessplating and photomask etching.

Next, referring to FIG. 12E, a cutting process is performed to cut theextension electrode layer E and the reflective protecting element 120along a cutting line to form a plurality of light-emitting devices 100 dseparated from one another. Each of the light-emitting devices 100 drespectively has at least one light-emitting unit 110 a, a reflectiveprotecting element 120 at least covering the side surface 116 a of thelight-emitting unit 110 a, a first extension electrode 130 d directly incontact with the first electrode pad 113, and a second extensionelectrode 140 directly in contact with the second electrode pad 115. Thefirst extension electrode 130 d and the second extension electrode 140 dare separated from each other and expose at least a portion of thebottom surface 124 of the reflective protecting element 120. At thispoint, the area of the first extension electrode 130 d can be greaterthan the area of the first electrode pad 113, and the area of the secondextension electrode 140 d can be greater than the area of the secondelectrode pad 115. The edges of the first extension electrode 130 d andthe edges of the second extension electrode 140 d are aligned with theedges of the reflective protecting element 120.

Lastly, referring further to FIG. 12E, the substrate 12 is removed toexpose the top surface 122 of the reflective protecting element 120 ofeach of the light-emitting devices 100 d and the upper surface 112 a ofthe light-emitting unit 110 a, wherein the top surface 122 of thereflective protecting element 120 of each of the light-emitting devices100 g is aligned with the upper surface 112 a of the light-emitting unit110 a. In another embodiment of the invention, the substrate 10 can alsobe removed first before a cutting process is performed.

FIG. 13A to FIG. 13D show cross sections of some of the steps of amanufacturing method of a light-emitting device of another embodiment ofthe invention. The main difference between the manufacturing method ofthe light-emitting device of the present embodiment and themanufacturing method of the light-emitting device in FIG. 12A to FIG.12E is that, between the steps of FIG. 12D and FIG. 12E, that is, afterthe extension electrode layer E is formed and before the cutting processis performed, referring to FIG. 13A, another substrate 20 is providedand disposed on the extension electrode layer E. Here, the material ofthe other substrate 20 is, for instance, stainless steel, ceramic, orother non-conductive materials. Next, referring further to FIG. 13A, thesubstrate 10 is removed after the other substrate 20 is provided toexpose the top surface 122 of the reflective protecting element 120 andthe upper surface 112 a of the light-emitting unit 110 a, wherein theupper surface 112 a of each of the light-emitting units 110 a is alignedwith the top surface 122 of the reflective protecting element 120.

Next, referring to FIG. 13B, the packaging adhesive layer 150 is formedon the light-emitting unit 110 a and the reflective protecting element120 to increase light extraction rate and improve light pattern. Here,the packaging adhesive layer 150 covers the upper surface 112 a of thelight-emitting unit 110 a and the top surface 122 of the reflectiveprotecting element 120, and at least one wavelength conversion materialcan also be doped inside the packaging adhesive layer 150. Thedescription of the wavelength conversion material is as provided in theembodiments above. Moreover, an oxide having high scattering power canalso be doped inside the packaging adhesive layer 150, such as titaniumdioxide (TiO₂) or silicon dioxide (SiO₂) to increase optical efficiency.

Next, referring to FIG. 13C, a translucent layer 160 is formed on thelight-emitting unit 110 a and the reflective protecting element 120,wherein the translucent layer 160 is located on the packaging adhesivelayer 150 and covers the packaging adhesive layer 150. For instance, thelight transmittance of the translucent layer 160 is greater than 50%.Here, the material of the translucent layer 160 is, for instance, glass,ceramic, resin, acrylic, or silicone, and the object thereof is to guidethe light generated by the light-emitting unit 110 a to the outside toeffectively increase luminous flux and light extraction rate of thesubsequent light-emitting device 100 i, and the light-emitting unit 110a can also be effectively protected to prevent impact from outside watervapor and oxygen.

Next, referring to FIG. 13D, a cutting process is performed to cut thetranslucent layer 160, the packaging adhesive layer 150, the reflectiveprotecting element 120, and the extension electrode layer E along thecutting line L to form a plurality of light-emitting devices 100 iseparated from one another. Lastly, referring further to FIG. 13D, theother substrate 20 is removed to expose the first extension electrode130 d and the second extension electrode 140 d of each of thelight-emitting devices 100 i. In another embodiment of the invention,the substrate 20 can also be removed first before a cutting process isperformed.

FIG. 14A to FIG. 14E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention. Referringfirst to FIG. 14A, a wavelength conversion adhesive layer 170 isprovided, wherein the wavelength conversion adhesive layer 170 includesa low-concentration fluorescent adhesive layer 174 and ahigh-concentration fluorescent adhesive layer 172 located on thelow-concentration fluorescent adhesive layer 174. Here, the steps offorming the wavelength conversion adhesive layer 170 include, forinstance, first mixing a dopant and a colloid (i.e., evenly mixing aliquid or molten colloid with a wavelength conversion material, and thewavelength conversion material is, for instance, fluorescent powder, butis not limited thereto) to form the wavelength conversion adhesive layer170. Next, the wavelength conversion adhesive layer 170 is left to standfor a period of time, such as 24 hours, to precipitate to form thehigh-concentration fluorescent adhesive layer 172 and thelow-concentration fluorescent adhesive layer 174 separated into upperand lower layers. In other words, the wavelength conversion layer 170 ofthe present embodiment is exemplified by two adhesive layers. Of course,in other embodiments, referring to FIG. 14A′, a wavelength conversionadhesive layer 170′ is provided as a single adhesive layer, which isstill within the scope of the invention.

Next, referring to FIG. 14B, a plurality of light-emitting units 110 carranged at intervals is disposed on the wavelength conversion adhesivelayer 170, wherein each of the light-emitting units 110 c has an uppersurface 112 c and a lower surface 114 c opposite to each other, a sidesurface 116 c connected to the upper surface 112 c and the lower surface114 c, and a first electrode pad 113 and a second electrode pad 115located on the lower surface 114 c and separated from each other, andthe upper surface 112 c of the light-emitting unit 110 c is located onthe high-concentration fluorescent adhesive layer 172 of the wavelengthconversion adhesive layer 170. Next, a plurality of translucent adhesivelayers 150 c for which the material contains a transparent colloid isformed on the wavelength conversion adhesive layer 170 and extended tothe side surface 116 c of the light-emitting unit 110 c, wherein thetranslucent adhesive layer 150 c does not completely cover the sidesurface 116 c of the light-emitting unit 110 c, but is as shown in FIG.14B in which the translucent adhesive layer 150 c has a curvatureinclined surface, and the thickness of the translucent adhesive layer150 c is greater toward the upper surface 112 c of the light-emittingunit 110 c, i.e., closer to the wavelength conversion adhesive layer170. Here, the object of the translucent adhesive layer 150 c is to fixthe position of the light-emitting unit 110 c.

It should be mentioned that, in other embodiments, referring to FIG.14B′, before the light-emitting units 110 c arranged at intervals aredisposed on the wavelength conversion adhesive layer 170, an uncuredtranslucent adhesive layer 150 c′ for which the material contains atranslucent adhesive layer can also be formed on the wavelengthconversion adhesive layer 170. After the light-emitting units 110 c aredisposed on the wavelength conversion adhesive layer 170 at intervals,the translucent adhesive layer 150 c′ can be extended and disposedbetween the light-emitting unit 110 c and the high-concentrationfluorescent adhesive layer 172.

Next, referring to both the FIG. 14B and FIG. 14C, after the translucentadhesive layer 150 c′ is cured, a first cutting process is performed tocut the wavelength conversion adhesive layer 170 to form a plurality ofunits 101 separated from one another, wherein each of the units 101respectively has at least one light-emitting unit 110 c and a wavelengthconversion adhesive layer 170 disposed on the upper surface 112 c of thelight-emitting units 110 c, and edges 171 at two sides of the wavelengthconversion adhesive layer 170 of each of the units 101 are extendedoutside the side surface 116 c of the light-emitting units 110 c. Next,referring further to FIG. 14C, the units 101 arranged at intervals aredisposed on a substrate 10. In the present embodiment, the material ofthe substrate 10 is, for instance, stainless steel, ceramic, or othernon-conductive materials, and is not particularly limited.

Next, referring to FIG. 14D, a reflective protecting element 120 c isformed on the substrate 10 to cover the side surface 116 c of thelight-emitting units 110 c of each of the units 101 and the edges 171 ofthe wavelength conversion adhesive layer 170. Here, the forming methodof the reflective protecting element 120 c is, for instance, dispensing,wherein the reflective protecting element 120 c directly covers thetranslucent adhesive layer 150 c and is extended along the translucentadhesive layer 150 c to cover the edges 171 of the wavelength conversionadhesive layer 170. The orthographic projections of the first electrodepad 113 and the second electrode pad 115 of the light-emitting units 110c on the substrate 10 are not overlapped with the orthographicprojection of the reflective protecting element 120 c on the substrate10. Here, the reflective protecting element 120 c is, for instance, awhite adhesive layer.

Lastly, referring to both FIG. 14D and FIG. 14E, a second cuttingprocess is performed to cut the reflective protecting element 120 c andremove the substrate 10 to form a plurality of light-emitting devices100 j separated from one another. Each of the light-emitting devices 100j respectively has at least one light-emitting unit 101 and a reflectiveprotecting element 120 c covering the side surface 116 c of thelight-emitting unit 110 c and the edges 171 of the wavelength conversionadhesive layer 170. After the substrate 10 is removed, a top surface 122c of the reflective protecting element 120 c of each of thelight-emitting devices 100 j and a top surface 173 of the wavelengthconversion adhesive layer 170 are exposed. In another embodiment of theinvention, the substrate 10 can also be removed first before a cuttingprocess is performed. At this point, the manufacture of thelight-emitting devices 100 j is complete.

In terms of structure, referring further to FIG. 14E, the light-emittingdevice 100 j of the present embodiment includes a light-emitting unit110 c, a reflective protecting element 120 c, a translucent adhesivelayer 150 c, and a wavelength conversion adhesive layer 170. Thewavelength conversion adhesive layer 170 is disposed on the uppersurface 112 c of the light-emitting unit 110 c, wherein the wavelengthconversion adhesive layer 170 includes a low-concentration fluorescentadhesive layer 174 and a high-concentration fluorescent adhesive layer172, and the high-concentration fluorescent adhesive layer 172 islocated between the low-concentration fluorescent adhesive layer 174 andthe light-emitting unit 110 c, and the edges 171 of the wavelengthconversion adhesive layer 170 are extended outside the side surface 116c of the light-emitting unit 110 c. Here, the low-concentrationfluorescent adhesive layer 174 can be used as a transparent protectivelayer to increase the number of water vapor transmission paths toeffectively block water vapor. The translucent adhesive layer 150 c isdisposed between the side surface 116 c of the light-emitting unit 110 cand the reflective protecting element 120 c to fix the position of thelight-emitting unit 110 c. The reflective protecting element 120 c ofthe present embodiment further covers the edges 171 of the wavelengthconversion adhesive layer 170 along the translucent adhesive layer 150 ccovering the side surface 116 c of the light-emitting unit 110 c, andtherefore the light-emitting device 100 j of the present embodiment doesnot need a known bearing bracket to support and fix the light-emittingunit 110 c, such that package thickness and manufacturing cost can beeffectively reduced. At the same time, the positive optical efficiencyof the light-emitting unit 110 c can also be effectively increased viathe reflective protecting element 120 c having high reflectivity. Here,the top surface 122 c of the reflective protecting element 120 c isembodied as aligned with the top surface 173 of the wavelengthconversion adhesive layer 170.

FIG. 15A to FIG. 15E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention. Referringfirst to FIG. 15A, a first release film 30 is provided, and then awavelength conversion adhesive layer 170 a is provided on the firstrelease film 30. The wavelength conversion adhesive layer 170 a can be asingle adhesive layer or a plurality of adhesive layers, and in thepresent embodiment, the wavelength conversion adhesive layer 170 aincludes a low-concentration fluorescent adhesive layer 174 a and ahigh-concentration fluorescent adhesive layer 172 a located on thelow-concentration fluorescent adhesive layer 174 a. Here, the steps offorming the wavelength conversion adhesive layer 170 a include, forinstance, first forming the wavelength conversion adhesive layer 170 ain the manner of mixing a dopant and a colloid, and then leaving thewavelength conversion adhesive layer 170 a to stand for a period oftime, such as 24 hours, to form the low-concentration fluorescentadhesive layer 172 a and the high-concentration fluorescent adhesivelayer 174 a separated from each other. Here, the first release film 30is, for instance, a double-sided adhesive film.

Next, referring further to FIG. 15A, a plurality of light-emitting units110 c arranged at intervals is disposed on the wavelength conversionadhesive layer 170A, wherein each of the light-emitting units 110 c hasan upper surface 112 c and a lower surface 114 c opposite to each other,a side surface 116 c connected to the upper surface 112 c and the lowersurface 114 c, and a first electrode pad 113 and a second electrode pad115 located on the lower surface 114 c and separated from each other,and the upper surface 112 c of the light-emitting unit 110 c is locatedon the high-concentration fluorescent adhesive layer 172 a of thewavelength conversion adhesive layer 170 a. Here, two adjacentlight-emitting units 110 c have a gap G, and the gap G is, for instance,700 microns. Next, a plurality of translucent adhesive layers 150 c isrespectively formed on the side surface 116 c of the light-emitting unit110 c, wherein the translucent adhesive layer 150 c does not completelycover the side surface 116 c of the light-emitting unit 110 c, but is asshown in FIG. 15B in which the translucent adhesive layer 150 c has acurvature inclined surface, and the thickness of the translucentadhesive layer 150 c is greater toward the upper surface 112 c of thelight-emitting unit 110 c. Here, the object of the translucent adhesivelayer 150 c is to fix the position of the light-emitting unit 110 c.

Next, referring to FIG. 15B, a first cutting process is performed to cutthe high-concentration fluorescent adhesive layer 172 a and a portion ofthe low-concentration fluorescent adhesive layer 174 a to form aplurality of trenches C. As shown in FIG. 15B, in the first cuttingprocess, the wavelength conversion adhesive layer 170 a is notcompletely cut off and only the high-concentration fluorescent adhesivelayer 172 is cut off and a portion of the low-concentration fluorescentadhesive layer 174 a is cut. Here, a width W of the trenches C is, forinstance, 400 microns, and a depth D of the trenches C is, for instance,half of a thickness T of the wavelength conversion adhesive layer 170 a.The thickness T of the wavelength conversion adhesive layer 170 a is,for instance, 140 microns, and the depth D of the trenches C is, forinstance, 70 microns. At this point, the position of the trenches C andthe position of the packaging adhesive layer 150 c do not interfere witheach other.

Next, referring to FIG. 15C, a reflective protecting element 120 d isformed on the low-concentration fluorescent adhesive layer 174 a tocover the side surface 116 c of the light-emitting unit 110 c, whereinthe reflective protecting element 120 d completely fills the trenches Cand exposes the first electrode pad 113 and the second electrode pad 115of the light-emitting unit 110 c. Here, the reflective protectingelement 120 d is, for instance, a white adhesive layer.

Lastly, referring to both FIG. 15D and FIG. 15E, the first release film30 is removed and a second release film 40 is provided such that thefirst electrode pad 113 and the second electrode pad 115 of thelight-emitting unit 110 c are in contact with the second release film40. Here, the second release film 40 is, for instance, a UV adhesive ordouble-sided adhesive. Next, a second cutting process is performed tocut the reflective protecting element 120 d and the low-concentrationfluorescent adhesive layer 174 a along the extending direction of thetrenches C (i.e., the extending direction of the cutting line L in FIG.15D) to form a plurality of light-emitting devices 100 k separated fromone another. Each of the light-emitting devices 100 k respectively hasat least one light-emitting unit 110, a wavelength conversion adhesivelayer 170 a disposed on the upper surface 112 c of the light-emittingunit 110 c, and a reflective protecting element 120 d covering the sidesurface 116 c of the light-emitting unit 110 c. In the presentembodiment, the wavelength conversion adhesive layer 170 a contains thehigh-concentration fluorescent adhesive layer 172 a and thelow-concentration fluorescent adhesive layer 174 a. Here, edges 171 a ofthe low-concentration fluorescent adhesive layer 174 a of the wavelengthconversion adhesive layer 170 a are aligned with edges 121 of thereflective protecting element 120 d, and the reflective protectingelement 120 d further covers edges 173 a of the high-concentrationfluorescent adhesive layer 172 a. The second release film 40 is removedto complete the manufacture of the light-emitting device 100 k.

In terms of structure, referring further to FIG. 15E, the light-emittingdevice 100 k of the present embodiment includes a light-emitting unit110 c, a reflective protecting element 120 d, a translucent adhesivelayer 150 c, and a wavelength conversion adhesive layer 170 a. Thewavelength conversion adhesive layer 170 a is disposed on the uppersurface 112 c of the light-emitting unit 110 c, wherein the wavelengthconversion adhesive layer 170 a includes a low-concentration fluorescentadhesive layer 174 a and a high-concentration fluorescent adhesive layer172 a, the high-concentration fluorescent adhesive layer 172 a islocated between the low-concentration fluorescent adhesive layer 174 aand the light-emitting unit 110 c, and the edges 171 a of the wavelengthconversion adhesive layer 170 a are extended outside the side surface116 c of the light-emitting unit 110 c. Here, the low-concentrationfluorescent adhesive layer 174 can be used as a transparent protectivelayer to increase the number of water vapor transmission paths toeffectively block water vapor. The translucent adhesive layer 150 c isdisposed between the side surface 116 c of the light-emitting unit 110 cand the reflective protecting element 120 d to fix the position of thelight-emitting unit 110 c. The reflective protecting element 120 d ofthe present embodiment further covers the two edges 173 a of thehigh-concentration fluorescent adhesive layer 172 a of the wavelengthconversion adhesive layer 170 a along the translucent adhesive layer 150c covering the side surface 116 c of the light-emitting unit 110 c, andtherefore the light-emitting device 100 k of the present embodiment doesnot need a known bearing bracket to support and fix the light-emittingunit 110 c, such that package thickness and manufacturing cost can beeffectively reduced. At the same time, the positive optical efficiencyof the light-emitting unit 110 c can also be effectively increased viathe reflective protecting element 120 d having high reflectivity.Moreover, the low-concentration fluorescent adhesive layer 174 a of thewavelength conversion adhesive layer 170 a of the present embodimentcovers a top surface 122 d of the reflective protecting element 120 d.In other words, the edges 173 a of the high-concentration fluorescentadhesive layer 172 a and the edges 171 a of the low-concentrationfluorescent adhesive layer 174 a of the wavelength conversion adhesivelayer 170 a of the present embodiment are not aligned.

In other embodiments, referring to FIG. 16A, a light-emitting device 100m of the present embodiment is similar to the light-emitting device 100j in FIG. 14E, and the difference is that, a reflective protectingelement 120 m of the present embodiment completely fills a gap S betweenthe first electrode pad 113 and the second electrode pad 114 andcompletely covers a first side surface 113 b of the first electrode pad113 and a second side surface 115 b of the second electrode pad 115, anda bottom surface 124 m of the reflective protecting element 120 m isaligned with the first bottom surface 113 a of the first electrode pad113 and the second bottom surface 115 a of the second electrode pad 115.As a result, light leakage to the bottom of the light-emitting device100 m can be prevented. Moreover, the reflective protecting element 120m completely covers the two edges of the wavelength conversion adhesivelayer 170 a. Moreover, since the coverage of the reflective protectingelement 120 m is good and the reflective protecting element 120 m hasbetter structural strength, the light-emitting device 100 m of thepresent embodiment does not need a known bearing bracket to support andfix the light-emitting unit 110 c, such that package thickness andmanufacturing cost can be effectively reduced.

Alternatively, referring to FIG. 16B, a light-emitting device 100 n ofthe present embodiment is similar to the light-emitting device 100 k inFIG. 16A, and the difference is that, a reflective protecting element120 n of the present embodiment is filled in the gap S between the firstelectrode pad 113 and the second electrode pad 114 but does notcompletely fill the gap S, and the reflective protecting element 120 nonly covers a portion of the first side surface 113 b of the firstelectrode pad 113 and a portion of the second side surface 115 b of thesecond electrode pad 115. In other words, a height difference H existsbetween a bottom surface 124 n of the reflective protecting element 120n and the first bottom surface 113 a of the first electrode pad 113 andthe second bottom surface 115 a of the second electrode pad 115.Alternatively, referring to FIG. 16C, a light-emitting device 100 p ofthe present embodiment is similar to the light-emitting device 100 n inFIG. 16B, and the difference is that, a first electrode pad 113′ and asecond electrode pad 115′ in the present embodiment are embodied as aplurality of metal layers, such as formed by a first metal layer M1 anda second metal layer M2, but are not limited thereto. A reflectiveprotecting element 120 p completely covers the side surface of the firstmetal layer M1 of the first electrode pad 113′ and the second electrodepad 115 but does not completely cover the side surface of the secondmetal layer M2 of the first electrode pad 113′ and the second electrodepad 115′. In short, the first electrode pads 113 and 113′ and the secondelectrode pads 115 and 115′ of the light-emitting units 110 c and 110 c′of the light-emitting devices 100 m, 100 n, and 100 p can be a singlemetal layer or a plurality of metal layers and are not particularlylimited.

FIG. 17A to FIG. 17E show cross sections of a manufacturing method of alight-emitting device of an embodiment of the invention. Regarding themanufacturing method of the light-emitting device of the presentembodiment, first, referring to FIG. 17A, a wavelength conversionadhesive layer 210 is provided. The wavelength conversion adhesive layer210 can be a single adhesive layer or a plurality of adhesive layers,and the wavelength conversion adhesive layer 210 in the presentembodiment includes a low-concentration fluorescent adhesive layer 212and a high-concentration fluorescent adhesive layer 214 located on thelow-concentration fluorescent adhesive layer 212. Here, the steps offorming the wavelength conversion adhesive layer 210 include, forinstance, first laying a wavelength conversion adhesive material layer(not shown) formed by evenly mixing a fluorescent power (not shown) andsilicone (not shown) in the manner of mixing a dopant and a colloid on arelease film (not shown), and then leaving the wavelength conversionadhesive material layer to stand for a period of time, such as 24 hours,and a wavelength conversion adhesive layer 210 having alow-concentration fluorescent adhesive layer 212 and ahigh-concentration fluorescent adhesive layer 214 separated from eachother is formed due to the density difference between the fluorescentpowder and the silicone, wherein the high-concentration fluorescentadhesive layer 214 is precipitated below the low-concentrationfluorescent adhesive layer 212, the high-concentration fluorescentadhesive layer 214 is, for instance, yellow, the low-concentrationfluorescent adhesive layer 212 is, for instance, transparent, thethickness of the low-concentration fluorescent adhesive layer 212 ispreferably greater than the thickness of the high-concentrationfluorescent adhesive layer 214, and in an embodiment, the ratio of thethicknesses can be between 1 and 200, but is not limited thereto.

Next, referring further to FIG. 17A, a double-sided adhesive film 10 ais provided. The low-concentration fluorescent adhesive layer 212 of thewavelength conversion adhesive layer 210 is disposed on the double-sidedadhesive film 10 a to fix the position of the wavelength conversionadhesive layer 210 via the double-sided adhesive film 10 a. Next, afirst cutting process is performed to cut from the high-concentrationfluorescent adhesive layer 214 to a portion of the low-concentrationfluorescent adhesive layer 212 to form a plurality of trenches C1. Here,the depth of each of the trenches C1 is at least half of the thicknessof the wavelength conversion adhesive layer 210. For instance, if thethickness of the wavelength conversion adhesive layer 210 is 240microns, then the depth of the trenches C1 is, for instance, 200microns. At this point, the trenches C1 can divide the low-concentrationfluorescent adhesive layer 212 of the wavelength conversion adhesivelayer 210 into a mesa portion 212 a and a protruding portion 212 blocated on the mesa portion 212 a, and the high-concentrationfluorescent adhesive layer 214 is located on the protruding portion 212b.

Next, referring to FIG. 17B, a plurality of light-emitting units 220arranged at intervals is disposed on the wavelength conversion adhesivelayer 210, wherein each of the light-emitting units 220 has an uppersurface 222 and a lower surface 224 opposite to each other, a sidesurface 226 connected to the upper surface 222 and the lower surface224, and a first electrode pad 223 and a second electrode pad 225located on the lower surface 224 and separated from each other. Theupper surface 222 of the light-emitting unit 220 is located on thehigh-concentration fluorescent adhesive layer 214 of the wavelengthconversion adhesive layer 210 to increase light extraction rate andimprove light type. The trenches C1 divide the light-emitting unit 220into a plurality of units A, and each of the units A in the presentembodiment at least includes two light-emitting units 220 (FIG. 17Bschematically shows two light-emitting units 220). Each of thelight-emitting units 220 is, for instance, an LED chip having anemission wavelength between 315 nm and 780 nm, and the LED chipincludes, but is not limited to, a UV, blue, green, yellow, orange, orred LED chip.

Next, referring further to FIG. 17B, a translucent adhesive layer 230 ais formed on the wavelength conversion adhesive layer 210 and extendedand disposed on the side surface 226 of the light-emitting unit 220. Asshown in FIG. 17B, the thickness of the translucent adhesive layer 230 ais gradually increased from the lower surface 224 toward the uppersurface 222 of each of the light-emitting units 220, and the translucentadhesive layer 230 a has a concave surface 232 relative to the sidesurface 226 of the light-emitting unit 220, but is not limited thereto.Here, the object of the translucent adhesive layer 230 a is to fix theposition of the light-emitting units 220, and since the translucentadhesive layer 230 a is a translucent material and has an index ofrefraction greater than 1, the light extraction effect of the side ofthe chip can also be increased.

Next referring to FIG. 17C, a reflective protecting element 240 isformed between the light-emitting units 220 and completely fills thetrenches C1, wherein the reflective protecting element 240 is formed onthe wavelength conversion adhesive layer 210 and covers each of theunits A and completely fills the trenches C1. The reflective protectingelement 240 exposes the lower surface 224, the first electrode pad 223,and the second electrode pad 225 of each of the light-emitting units220. Here, the index of refraction of the reflective protecting element240 is at least greater than 90%, and the reflective protecting element240 is, for instance, a white adhesive layer. The forming method of thereflective protecting element 240 is, for instance, dispensing, whereinthe reflective protecting element 240 directly covers the translucentadhesive layer 230 a and is extended to cover the edges of thehigh-concentration fluorescent adhesive layer 214 along the translucentadhesive layer 230 a and completely fills the trenches C1. At thispoint, the orthographic projections of the first electrode pad 223 andthe second electrode pad 225 of the light-emitting units 220 on thedouble-sided adhesive film 10 a are not overlapped with the orthographicprojection of the reflective protecting element 240 on the double-sidedadhesive film 10 a.

Next, referring further to FIG. 17C, a second cutting process isperformed from the reflective protecting element 240 along the trenchesC1 through the low-concentration fluorescent adhesive layer 212 to forma plurality of light-emitting devices 200 a separated from one another.At this point, as shown in FIG. 17C, the wavelength conversion adhesivelayer 210 in contact with two light-emitting units 220 in each of theunits A is continuous. That is, the light-emitting units 220 have thesame light-emitting surface, and therefore the light emitted by thelight-emitting units 220 can be guided by the transparentlow-concentration fluorescent adhesive layer 212 such that thelight-emitting devices 200 a of the present embodiment have betterluminance uniformity.

Next, referring to both FIG. 17C and FIG. 17D, after a second cuttingprocess is performed, a film-turning process is needed. First, a UVadhesive film 20 a is provided on the first electrode pad 223 and thesecond electrode pad 225 of the light-emitting units 220 to first fixthe relative positions of the light-emitting devices 200 a. Next, thedouble-sided adhesive film 10 a is removed to expose thelow-concentration fluorescent adhesive layer 212 of the wavelengthconversion adhesive layer 210. Lastly, referring to FIG. 17E, the UVadhesive film 20 a is removed to expose the first electrode pad 223 andthe second electrode pad 225 of the light-emitting units 220. At thispoint, the manufacture of the light-emitting devices 200 a is complete.It should be mentioned that, for ease of explanation, FIG. 17E onlyschematically shows one light-emitting device 200 a.

In terms of structure, referring further to FIG. 17E, the light-emittingdevice 200 a includes a plurality of light-emitting units 220 (FIG. 17Eschematically shows two light-emitting units 220), a wavelengthconversion adhesive layer 210, and a reflective protecting element 240.Each of the light-emitting units 220 has an upper surface 222 and alower surface 224 opposite to each other, a side surface 226 connectedto the upper surface 222 and the lower surface 224, and a firstelectrode pad 223 and a second electrode pad 225 located on the lowersurface 224 and separated from each other. The wavelength conversionadhesive layer 210 is disposed on the upper surface 222 of thelight-emitting unit 220, and the wavelength conversion adhesive layer210 includes a low-concentration fluorescent adhesive layer 212 and ahigh-concentration fluorescent adhesive layer 214. The low-concentrationfluorescent adhesive layer 212 has a mesa portion 212 a and a protrudingportion 212 b located on the mesa portion 212 a. The high-concentrationfluorescent adhesive layer 214 is disposed between the upper surface 222and the protruding portion 212 b, wherein the high-concentrationfluorescent adhesive layer 214 covers the protruding portion 212 b andis in contact with the upper surface 222 of the light-emitting unit 220.The light-emitting units 220 are arranged at intervals and expose aportion of the wavelength conversion adhesive layer 210. The reflectiveprotecting element 240 covers the side surface 226 of each of thelight-emitting units 220 and covers the wavelength conversion adhesivelayer 210 exposed by the light-emitting units 220. The reflectiveprotecting element 240 exposes the lower surface 224, the firstelectrode pad 223, and the second electrode pad 225 of each of thelight-emitting units 220. The edges of the reflective protecting element240 are aligned with the edges of the mesa portion 212 a of thelow-concentration fluorescent adhesive layer 212.

The light-emitting units 220 in the light-emitting device 200 a of thepresent embodiment are only in contact with one wavelength conversionadhesive layer 210, i.e., the light-emitting units 220 have the sameluminous surface, and the edges of the low-concentration fluorescentadhesive layer 212 are aligned with the edges of the reflectiveprotecting element 240. Therefore, the light emitted by thelight-emitting units 220 is guided by the low-concentration fluorescentadhesive layer 212 such that the light-emitting device 200 a of thepresent embodiment can have a greater luminous area and better luminanceuniformity. Moreover, the reflective protecting element 240 covers theside surface 226 of the light-emitting units 220, and the reflectiveprotecting element 240 exposes the first electrode pad 223 and thesecond electrode pad 225 of the light-emitting units 220. Therefore, thelight-emitting device 200 a of the present embodiment does not need aknown bearing bracket to support and fix the light-emitting units 220,such that package thickness and manufacturing cost can be effectivelyreduced. At the same time, the positive optical efficiency of thelight-emitting units 220 can also be effectively increased.

It should be mentioned that, in the present embodiment, the structuraltype of the translucent adhesive layer 230 a is not limited, even thoughthe translucent adhesive layer 230 a shown in FIG. 17E is embodied ashaving a concave surface 232 relative to the side surface 226 of thelight-emitting units 220. In other words, the reflective protectingelement 240 further contains a reflective surface 242 in contact withthe light-emitting units 220, and the reflecting surface 242 is embodiedas a curved surface. However, in other embodiments, referring to FIG.18A, a light-emitting device 200 b of the present embodiment is similarto the light-emitting device 200 a in FIG. 17E, and the difference isthat, a translucent adhesive layer 230 b has a convex surface 234relative to the side surface 226 of each of the light-emitting units 220to effectively increase the lateral emission of the light-emitting units220. Moreover, with the configuration of the wavelength conversionadhesive layer 210, the emission area of the light-emitting device 200 bcan also be increased. In other words, a reflective surface 242 a of thereflective protecting element 240 a is embodied as a curved surface.Alternatively, referring to FIG. 18B, a light-emitting device 200 c ofthe present embodiment is similar to the light-emitting device 200 a inFIG. 17E, and the difference is that, a translucent adhesive layer 230 chas an inclined surface 236 relative to the side surface 226 of each ofthe light-emitting units 220. In other words, a reflective surface 242 bof a reflective protecting element 240 b is embodied as a flat surface.

It should be mentioned here that, the following embodiments adopt thereference numerals of the embodiments above and a portion of thecontents thereof, wherein the same reference numerals are adopted torepresent the same or similar elements. Descriptions of the sametechnical content are as provided in the embodiments above and are notrepeated in the following embodiments.

FIG. 19A to FIG. 19E show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention. The maindifference between the manufacturing method of a light-emitting device200 d of the present embodiment and the manufacturing method of thelight-emitting device 200 a in FIG. 17A to FIG. 17E is that, referringto FIG. 19A, during the first cutting process, a plurality of secondtrenches C2′ cut from a high-concentration fluorescent adhesive layer214′ to a portion of a low-concentration fluorescent adhesive layer 212′is further formed. As shown in FIG. 19A, the positions of the trenchesC1′ and the second trenches C2′ are alternately arranged, wherein thedepth of each of the trenches C1′ is at least half of the thickness ofthe wavelength conversion adhesive layer 210′, and the depth of each ofthe second trenches C2′ is the same as the depth of each of the trenchesC1′. For instance, the thickness of the wavelength conversion adhesivelayer 210′ is 240 microns and the depth of the trenches C1′ and thedepth of the second trenches C2′ are, for instance, 200 microns, but arenot limited thereto. At this point, a mesa portion 212 a′ of thelow-concentration fluorescent adhesive layer 212′ has a thickness T, andpreferably, the thickness T is, for instance, between 20 microns and 50microns. The second trenches C2′ divide the protruding portion of thelow-concentration fluorescent adhesive layer 212′ in the wavelengthconversion adhesive layer 210′ into two protruding sub-portions 212 b′,and the high-concentration fluorescent adhesive layer 214′ is located onthe protruding sub-portions 212 b′.

Next, referring to FIG. 19B, the light-emitting units 220 arranged atintervals are disposed on the wavelength conversion adhesive layer 210′,wherein the second trenches C2′ are located between two light-emittingunits 220 of each of the light-emitting units A, the light-emittingunits 220 are respectively disposed on the protruding sub-portions 212b′, and the upper surface 222 of the light-emitting units 220 is indirect contact with the high-concentration fluorescent adhesive layer214′. Preferably, the ratio of the length of each of the protrudingsub-portions 212 b′ and the length of the corresponding light-emittingunit 220 is greater than 1 and less than 1.35. In other words, the edgesof the protruding sub-portions 212 b′ of the low-concentrationfluorescent adhesive layer 212′ are outside the edges of thelight-emitting units 220, and the edges of the high-concentrationfluorescent adhesive layer 214′ are also extended outside the edges ofthe light-emitting units 220 to effectively increase the luminous areaof the light-emitting units 220. Next, a translucent adhesive layer 230a is respectively formed on the side surface 226 of the light-emittingunits 220, wherein the translucent adhesive layer 226 is only disposedon the side surface 226 of the light-emitting units 220 and extendedonto the high-concentration fluorescent adhesive layer 214′ of thewavelength conversion adhesive layer 210′ and is not extended anddisposed on the low-concentration fluorescent adhesive layer 212′.

Next, similar to the steps of FIG. 17C, FIG. 17D, and FIG. 17E,referring first to FIG. 19C, a reflective protecting element 240 isformed on the wavelength conversion adhesive layer 210′ to cover each ofthe units A and completely fill the trenches C1′ and the second trenchesC2′. Next, a second cutting process is performed from the reflectiveprotecting element 240 along the trenches C1′ through thelow-concentration fluorescent adhesive layer 212′ to form a plurality oflight-emitting devices 200 d separated from one another. Next, referringto both FIG. 19C and FIG. 19D, after a second cutting process isperformed, a film-turning process is needed. First, a UV adhesive film20 a is provided on the first electrode pad 223 and the second electrodepad 225 of the light-emitting units 220 to first fix the relativepositions of the light-emitting devices 200 a. Next, the double-sidedadhesive film 10 a is removed to expose the low-concentrationfluorescent adhesive layer 212′ of the wavelength conversion adhesivelayer 210′. Lastly, referring to FIG. 19E, the UV adhesive film 20 a isremoved to expose the first electrode pad 223 and the second electrodepad 225 of the light-emitting units 220. At this point, the manufactureof the light-emitting devices 200 d is complete. It should be mentionedthat, for ease of explanation, FIG. 19E only schematically shows onelight-emitting device 200 d.

Referring to all of FIG. 19E, FIG. 20A, and FIG. 20B, it should bementioned that, FIG. 19E shows a cross section along line Y-Y in FIG.20A. The light-emitting device 200 d of the present embodiment issimilar to the light-emitting device 200 a in FIG. 17E, and thedifference is that, the wavelength conversion adhesive layer 210′exposed between two light-emitting units 220 further has the secondtrenches C2′, wherein the second trenches C2′ are extended from thehigh-concentration fluorescent adhesive layer 214′ to a portion of thelow-concentration fluorescent adhesive layer 212′. In other words, twolight-emitting units 220 are disposed on one continuous wavelengthconversion adhesive layer 210′, and therefore the light-emitting units220 have the same light-emitting surface, and the edges of thelow-concentration fluorescent adhesive layer 212′ are aligned with theedges of the reflective protecting element 240. Therefore, the lightemitted by the light-emitting units 220 is guided by thelow-concentration fluorescent adhesive layer 212′ such that thelight-emitting device 200 d of the present embodiment can have a greaterluminous area and better luminance uniformity.

In particular, during the first cutting process, the depths cut alongline X-X and line Y-Y in FIG. 20A are substantially the same. In otherwords, referring to FIG. 20B, in the cross section of line X-X, the mesaportion 212 a′ of the low-concentration fluorescent adhesive layer 212′has a thickness T, and referring to FIG. 19E, in the cross section ofline Y-Y, the mesa portion 212 a′ of the low-concentration fluorescentadhesive layer 212′ also has the thickness T. Preferably, the thicknessT is, for instance, between 20 microns and 50 microns.

Of course, in other embodiments, during the first cutting process, whencutting in different directions, the mesa portion 212 a′ of thelow-concentration fluorescent adhesive layer 212′ can also have adifferent thickness. FIG. 21A shows a 3D view of a light-emitting deviceof another embodiment of the invention. FIG. 21B and FIG. 21Crespectively show cross sections along line X′-X′ and line Y′-Y′ of FIG.21A. Referring to all of FIG. 21A, FIG. 21B, and FIG. 21C, during thefirst cutting process, the depths cut along line X′-X′ and line Y′-Y′ inFIG. 21A are different, such that the wavelength conversion adhesivelayer 210′ further includes a first exposed side portion and a secondexposed side portion not covered by the reflective protecting element240. The first exposed side portion and the second exposed side portionare not parallel, and the thickness of the wavelength conversionadhesive layer 210′ at the first exposed side portion is different fromthe thickness of the wavelength conversion adhesive layer 210′ at thesecond exposed side portion. Specifically, a mesa portion 212 a″ of alow-concentration fluorescent adhesive layer 212″ has a first thicknessT1 along line X′-X′, the mesa portion 212 a″ of the low-concentrationfluorescent adhesive layer 212″ has a second thickness T2 along lineY′-Y′, and the first thickness T1 is different from the second thicknessT2. Preferably, the first thickness T1 is, for instance, between 50microns and 200 microns, and the second thickness T2 is, for instance,between 20 microns and 50 microns.

Since the mesa portion 212 a″ of the low-concentration fluorescentadhesive layer 212″ of the present embodiment respectively has the firstthickness T1 and the second thickness T2 different from each other alongline X′-X′ and line Y′-Y′, the occurrence of reduced brightness causedby dark bands between two adjacent light-emitting units 220 can beeffectively reduced to increase the luminance uniformity of thelight-emitting device 200 e. Moreover, it should be mentioned that,using line Y′-Y′ as an example, when the thickness T2 of the mesaportion 212 a″ of a low-concentration fluorescent adhesive layer 212′″is increased from, for instance, 0.04 mm to 0.2 mm, the light-emittingangle of the light-emitting units 220 can also be increased from theoriginal 120 degrees to 130 degrees, i.e., the light-emitting angle ofthe light-emitting units 220 can be increased by 10 degrees. In short,the thickness of the mesa portion 212 a″ of the low-concentrationfluorescent adhesive layer 212′″ is positively correlated to thelight-emitting angle of the light-emitting units 220.

FIG. 22A to FIG. 22J show cross sections of a manufacturing method of alight-emitting device of another embodiment of the invention. FIG. 23shows a comparison chart of color temperature of the light-emittingdevice of the embodiment of FIG. 22J and a known LED structure measuredat different angles.

Referring to FIG. 22A, a first release film 30 is provided. The firstrelease film 30 is, for instance, a double-sided adhesive film. Next, awavelength conversion adhesive layer 170 b is provided on the firstrelease film 30. The wavelength conversion adhesive layer 170 b can be asingle adhesive layer or a plurality of adhesive layers, and in thepresent embodiment, the wavelength conversion adhesive layer 170 bincludes a low-concentration fluorescent adhesive layer 174 b and ahigh-concentration fluorescent adhesive layer 172 b located on thelow-concentration fluorescent adhesive layer 174 b. Here, the steps offorming the wavelength conversion adhesive layer 170 b include, forinstance, first forming the wavelength conversion adhesive layer 170 bin the manner of mixing a dopant and a colloid, and then leaving thewavelength conversion adhesive layer 170 b to stand for a period oftime, such as 24 hours, to form the low-concentration fluorescentadhesive layer 174 b and the high-concentration fluorescent adhesivelayer 172 b separated from each other. Moreover, the wavelengthconversion adhesive layer 170 b is heated and baked to cure and mold thelow-concentration fluorescent adhesive layer 174 b and thehigh-concentration fluorescent adhesive layer 172 b.

Referring to FIG. 22B, a plurality of light-emitting units 110 e (threein this case, but not limited thereto) is provided, wherein each of thelight-emitting units 110 e has an upper surface 112 e and a lowersurface 114 e opposite to each other, a side surface 116 e connected tothe upper surface 112 e and the lower surface 114 e, and a firstelectrode pad 113 and a second electrode pad 115 located on the lowersurface 114 e and separated from each other. The width of each of thelight-emitting units 110 e is W_(E). The light-emitting units 110 e are,for instance, LED structures.

Referring to FIG. 22C and FIG. 22D, a plurality of trenches C″ is formedin the wavelength conversion adhesive layer 170 b to define a pluralityof bonding regions BA between the trenches C″. Referring first to FIG.22C, first, a portion of the high-concentration fluorescent adhesivelayer 172 b and a portion of the low-concentration fluorescent adhesivelayer 174 b in the wavelength conversion adhesive layer 170 b areremoved to form a plurality of first sub-trenches C1″. The firstsub-trenches C1″ respectively form a plurality of first mesa portions P1in the bonding regions BA. Each of the first mesa portions P1 furtherincludes a first portion 172 b 1 of the high-concentration fluorescentadhesive layer 172 b and a first portion 174 b 1 of thelow-concentration fluorescent adhesive layer 174 b. The first portion172 b 1 of the high-concentration fluorescent adhesive layer 172 b isdisposed on the first portion 174 b of the low-concentration fluorescentadhesive layer 174 b. Next, referring to FIG. 22D, a portion of thelow-concentration fluorescent adhesive layer 174 b is removed to form aplurality of second sub-trenches C2″ in the first sub-trenches C1″. Thesecond sub-trenches C2″ respectively form a plurality of second mesaportions P2 in the bonding regions BA. Each of the second mesa portionsP2 further includes a second portion 174 b 2 of the low-concentrationfluorescent adhesive layer 174, and the first portion 174 b 1 of thelow-concentration fluorescent adhesive layer 174 b and the secondportion 174 b 2 of the low-concentration fluorescent adhesive layer 174b are connected to each other. A trench C′ includes a first sub-trenchC1″ and a second sub-trench C2″. In the bonding regions BA, the width ofthe high-concentration fluorescent adhesive layer 172 b 1 is W_(H), thewidth of the low-concentration fluorescent adhesive layer 174 b isW_(L), the width of the light-emitting units 110 e is W_(E), and thestep further satisfies the following inequalities: W_(E)<W_(L),W_(H)<W_(L), and 0.8<W_(H)/W_(E)≤1.2.

Referring to FIG. 22E, a plurality of translucent adhesive layers 150 eis respectively formed on the high-concentration fluorescent adhesivelayers 172 b in the bonding regions BA. The translucent adhesive layer150 e is, for instance, silicone.

Referring to FIG. 22F, the upper surfaces 112 e of the light-emittingunits 110 e are respectively bonded to the high-concentrationfluorescent adhesive layers 172 b in the bonding regions BA via thetranslucent adhesive layers 150 e. Due to the capillarity phenomenon,the translucent adhesive layer 150 e has a curvature inclined surface,and the thickness of the translucent adhesive layer 150 e is greatertoward the upper surface 112 e of the light-emitting units 110 e. Here,the object of the translucent adhesive layer 150 e is to fix theposition of the light-emitting units 110 e.

Referring to FIG. 22G, a reflective protecting element 120 e is formedon the wavelength conversion adhesive layer 170 b and between thelight-emitting units 110 e to completely fill the trenches C″. Thereflective protecting element 120 e exposes the electrode pads 113 and115 of the light-emitting units 110 e. Here, the reflective protectingelement 120 e is, for instance, a white adhesive layer.

Referring to FIG. 22H, the reflective protecting element 120 e is leftto stand such that the reflective protecting element 120 e forms aconcave surface CS toward the wavelength conversion adhesive layer 170b. Next, the reflective protecting element 120 e is cured to fix theshape of the reflective protecting element 120 e.

Lastly, referring to both FIG. 22I and FIG. 22J, a cutting process isperformed to cut the reflective protecting element 120 e and thelow-concentration fluorescent adhesive layer 174 b along the extendingdirection of the trenches C″ to form a plurality of light-emittingdevices 100 q separated from one another. Moreover, the first releaselayer 30 is removed. At this point, the manufacture of thelight-emitting devices 100 q is complete.

Referring further to FIG. 22J, in terms of structure, the light-emittingdevice 100 q of the present embodiment includes a light-emitting unit110 e, a reflective protecting element 120 e, a transparent adhesivelayer 150 e, and a wavelength conversion adhesive layer 170 b. Theconfiguration relationship between each element is described in detailbelow.

The wavelength conversion adhesive layer 170 b is disposed on the uppersurface 112 e of the light-emitting unit 110 e. The wavelengthconversion adhesive layer 170 b includes a low-concentration fluorescentadhesive layer 174 b and a high-concentration fluorescent adhesive layer172 b, and the high-concentration fluorescent adhesive layer 172 b islocated between the low-concentration fluorescent adhesive layer 174 band the light-emitting unit 110 e. More specifically, the wavelengthconversion adhesive layer 170 b further includes a first mesa portion P1and a plurality of second mesa portions P2. The second mesa portions P2are located at two opposite sides of the first mesa portion P1. Thefirst mesa portion P1 includes a first portion 174 b 1 of thehigh-concentration fluorescent adhesive layer 172 b and thelow-concentration fluorescent adhesive layer 174 b. The second mesaportion P2 includes a second portion 174 b 2 of the low-concentrationfluorescent adhesive layer 174 b. The first portion 174 b 1 of thelow-concentration fluorescent adhesive layer 174 b and the secondportion 174 b 2 of the low-concentration fluorescent adhesive layer 174b are connected to each other.

The reflective protecting element 120 e covers the light-emitting unit110 e and a portion of the wavelength conversion adhesive layer 170 band at least exposes the two electrode pads 113 and 115 of thelight-emitting unit 110 e and the low-concentration fluorescent layer174 b. The reflective protecting element 120 e has a reflective surfaceRS, and the reflective surface RS is in contact with the light-emittingunit 110 e. More specifically, the reflective surface RS is a curvedsurface, and the first side of the reflective surface RS is in contactwith the light-emitting unit 110 e, and the second side of thereflective surface RS is extended toward the wavelength conversionadhesive layer 170 b and away from the light-emitting unit 110 e. Thereflective protecting element 120 e has a concave surface CS. Theconcave surface CS is recessed toward the wavelength conversion adhesivelayer 170 b and faces the outside. When the light-emitting device 100 qof the present embodiment is connected to an external substrate (such asthe backplane, printed circuit board, or other types of substrates in adisplay panel), since the surface of the reflective protecting element120 e exposed to the outside is a concave surface CS, a gap between thelight-emitting device 100 q and an external substrate caused by aprotrusion of the reflective protecting element 120 e can be prevented.The generation of the gap causes unsatisfactory bonding between theelectrode pads 113 and 115 of the light-emitting unit 110 e and theexternal substrate.

The transparent adhesive layer 150 e is disposed on thelow-concentration fluorescent adhesive layer 174 b and extended to theside surface 116 e of the light-emitting unit 110 e. The translucentadhesive layer 150 e covers the side surface 116 e of the light-emittingunit 110 e, the high-concentration fluorescent adhesive layer 172 b, anda portion of the low-concentration fluorescent adhesive layer 174 b.

Referring to FIG. 22J and FIG. 23, in the light-emitting device 100 q ofthe present embodiment, the width of the high-concentration fluorescentadhesive layer 172 b is W_(H), the width of the low-concentrationfluorescent adhesive layer 174 b is W_(L), and the width of thelight-emitting unit 110 e is W_(E). The light-emitting device 100 qfurther satisfies the following inequalities: W_(E)<W_(L), W_(H)<W_(L)and 0.8<W_(H)/W_(E)≤1.2. The light-emitting device 100 q of the presentembodiment satisfies the inequality design above, and therefore a beamL1 (greater beam intensity) correspondingly emitted by thelight-emitting unit 110 e adjacent to the optical axis passes throughthe high-concentration fluorescent adhesive layer 172 b and thelow-concentration fluorescent adhesive layer 174 b adjacent to theoptical axis in order, and a beam L2 correspondingly emitted by thelight-emitting unit 110 e away from the optical axis (weaker beamintensity) passes through the translucent adhesive layer 150 e and thelow-concentration fluorescent adhesive layer 174 b away from the opticalaxis. Therefore, the light intensity of a conversion beam L1′ excited bythe beam L1 of the high-concentration fluorescent adhesive layer 172 band the low-concentration fluorescent adhesive layer 174 b adjacent tothe optical axis is greater than the light intensity of a conversionbeam L2′ excited by the beam L2 of the low-concentration fluorescentadhesive layer 174 b away from the optical axis. The light intensityratio between the beam L1 and the conversion beam L1′ and the lightintensity ratio between the beam L2 and the conversion beam L2′ are moreconsistent. As shown in FIG. 23, in comparison to the color lightemitted by a known LED structure, the color temperature of the colorlight emitted by the light-emitting device 100 q of the presentembodiment at different angles is more consistent.

It should be mentioned that, in the light-emitting device 100 q of thepresent embodiment, the color temperature of the color light emitted bythe light-emitting device 100 q at different angles can be furtheradjusted by adjusting variables such as the thickness and width of thehigh-concentration fluorescent adhesive layer 172 b 2 and thelow-concentration fluorescent adhesive layer 174 b in the wavelengthconversion adhesive layer 170 b at different positions.

Based on the above, in the light-emitting device of an embodiment of theinvention, the width of the high-concentration fluorescent adhesivelayer is W_(H), the width of the low-concentration fluorescent adhesivelayer is W_(L), and the width of the light-emitting unit is W_(E). Thelight-emitting device further satisfies the following inequalities:W_(E)<W_(L), W_(H)<W_(L) and 0.8<W_(H)/W_(E)≤1.2. By satisfying theinequality design above, the optical path of the beam (greater beamintensity) correspondingly emitted by the light-emitting unit adjacentto the optical axis passes through the fluorescent adhesive layer havinga greater concentration in the light-emitting device, and the opticalpath of the beam (weaker beam intensity) correspondingly emitted by thelight-emitting unit away from the optical axis passes through thefluorescent adhesive layer having a smaller concentration in thelight-emitting device. Therefore, the color temperature of the colorlight emitted by the light-emitting device of an embodiment of theinvention at different angles is more consistent. Since one of the stepsof the manufacturing method of the light-emitting device of anembodiment of the invention satisfies the above inequalities, the colortemperature of the color light emitted by the light-emitting device madeby the manufacturing method is more consistent at different angles.

Although the invention has been described with reference to the aboveembodiments, it will be apparent to one of ordinary skill in the artthat modifications to the described embodiments may be made withoutdeparting from the spirit of the invention. Accordingly, the scope ofthe invention is defined by the attached claims not by the abovedetailed descriptions.

What is claimed is:
 1. A light-emitting device, comprising: at least onelight-emitting unit, wherein the light-emitting unit has an uppersurface and a lower surface opposite to each other, the light-emittingunit comprises two electrode pads, and the two electrode pads arelocated on the lower surface of the light-emitting unit; a wavelengthconversion adhesive layer, disposed on the upper surface of thelight-emitting unit, wherein the wavelength conversion adhesive layercomprises a low-concentration fluorescent adhesive layer and ahigh-concentration fluorescent adhesive layer, and thehigh-concentration fluorescent adhesive layer is located between thelow-concentration fluorescent adhesive layer and the light-emittingunit; and a reflective protecting element, covering the light-emittingunit and a portion of the wavelength conversion adhesive layer and atleast exposing the two electrode pads of the light-emitting unit and thelow-concentration fluorescent layer, wherein a width of thehigh-concentration fluorescent adhesive layer is W_(H), a width of thelow-concentration fluorescent adhesive layer is W_(L), a width of thelight-emitting unit is W_(E), and the light-emitting device furthersatisfies the following inequalities:W _(E) <W _(L) ,W _(H) <W _(L); and0.8<W _(H) /W _(E)≤1.2.
 2. The light-emitting device of claim 1, whereinthe wavelength conversion adhesive layer further comprises a first mesaportion and a plurality of second mesa portions, the first mesa portioncomprises the high-concentration fluorescent adhesive layer and a firstportion of the low-concentration fluorescent adhesive layer, each of thesecond mesa portions comprises a second portion of the low-concentrationfluorescent adhesive layer, and the first portion of thelow-concentration fluorescent adhesive layer is connected to the secondportion of the low-concentration fluorescent adhesive layer.
 3. Thelight-emitting device of claim 1, wherein the reflective protectingelement has a concave surface, and the concave surface is recessedtoward the wavelength conversion adhesive layer.
 4. The light-emittingdevice of claim 1, further comprising a translucent adhesive layer,wherein the light-emitting unit further comprises a side surfaceconnected to the upper surface and the lower surface, and thetranslucent adhesive layer is disposed on the low-concentrationfluorescent adhesive layer and extended to the side surface of thelight-emitting unit.
 5. The light-emitting device of claim 1, whereinthe reflective protecting element covers the wavelength conversionadhesive layer and exposes a portion of a side of the wavelengthconversion adhesive layer.
 6. The light-emitting device of claim 1,wherein the reflective protecting element has a reflective surface, andthe reflective surface is in contact with the light-emitting unit. 7.The light-emitting device of claim 6, wherein a first side of thereflective surface is in contact with the light-emitting unit, and asecond side of the reflective surface is extended toward the wavelengthconversion adhesive layer and away from the light-emitting unit.
 8. Thelight-emitting device of claim 6, wherein the reflective surface is acurved surface.